Growth and result performance of 10 promising resistant lines of tungro disease in Lanrang South Sulawesi

Increased rice production is constrained by various limiting factors, One of these is tungro disease, which can limit productivity. When resistant tungro varieties are available, they are regarded as an affective control tool that is also more environmental friendly. Advanced yield experiment represents a phase in the process of producing cultivars that are resistant to tungro disease. The study aimed to determine the growth and result performance of tungro-resistant lines with greater phenotypic characteristics and yield potential compared to other tungro resistant varieties. The study was carried out from July to October 2018 at the Tungro Disease Research Station in Lanrang Sidrap, utilizing a design with a randomized complete block design, It was repeated three times using 10 tungro-resistant lines and two comparative varieties, namely Inpari 7, Lanrang, and Ciherang. The F test was used to examine the data, and the Least Significant Difference (LSD) test was used to determine significance. The parameters observed were Flowering age of 50% (days), number of panicles per m2, plant height (cm), density score, the weight of 1000 grains, number of filled and unfilled grains per panicle, moisture content (%), grain yield (kg/ha). Results revealed that there were four lines BP12280-3f-7-Kn-2-1*B-Lrg-1-1-10-9, BP12280-3f-7-Kn-2-1 * B-Lrg-1- 1-10-9, BP12206f-8-3-2 * B-LR-20-4 and BP12280-3f-7-Kn-2-1 * B-Lrg-1- 16-14 with a higher grain yield than Ciherang and Inpari 7 Lanrang, which benefited by 1000 grain weight, the number of grains filled per panicle and flowering age is 50% earlier than the comparison variety.


Introduction
Rice is the Indonesian people's main food.The increase in population directly demands an increase in national rice production.Pests and diseases are just some of the obstacles to increasing rice production.One of which is tungro disease is still challenges to increasing the production of rice, especially in endemic zones.In the 2021/2022 season, the incidence of rice tungro attacks in Indonesia is 1,295.98ha or 67.04% of the forecast number (1,933 ha) were the provinces of West Kalimantan, Central Kalimantan, South Kalimantan, Jambi, West Sulawesi, South Sulawesi, Maluku, and Aceh [1].
Tungro disease is brought on by a complex RTBV and RTSV infection, which can only be infected semi-persistently by green leafhoppers [2].Rice cultivars infected with the two viruses RTSV and RTBV exhibit stunting and yellow to orange leaf staining, as well as significantly lower grain quality [3].[4] describe the following symptoms of tungro: the most obvious symptoms are stunting of plants and yellowing of the leaves, other symptoms include poor root development, few tillers produced by infected plants, small, sterile panicles, and black blotches on the grains.Attempts to reduce tungro and boost rice productivity can be increased by plant breeding efforts [5] by developing new superior varieties that are considered quite successful [6] in suppressing tungro disease development [7].According to [8] two methods for improving resistance to tungro varieties are assembling strains with diverse resistance gene sources, for both viruses and vectors or constructing varieties based on parental compatibility using tungro virus variants and green leafhopper colonies.
Efforts To generate resistant cultivars with high yield, multiple selection processes are required, including potential yield trial, before release, perform an advanced yield trial and a multi-location test [9,10].The advanced yield experiment is the last step in the plant breeding process.Before releasing lines or varieties, it is necessary to verify their yield and adaptability [11].high yields, insect resistance, and high-yielding cultivars have traits like resistance to climatic change and disease, as well as desirable quality and flavor [10].Yield trials were carried out to assess the resistance of lines to tungro with high output [11,12]

Materials and methods
The study was carried out at the experimental garden Lanrang, Sidenrang Rappang District, South Sulawesi, Indonesia, on a rice field Dry Season of 2018.The materials consists of 10 tungro-resistant lines that have been tested for resistance by scoring tungro-resistant with the high resistance category (scoring 1) and two comparative varieties, Ciherang (high-yielding varieties and farmer preferences) and Inpari 7 Lanrang (tungro-resistant varieties).(Table 1).
The study used a randomized complete block design with three replications, yielding 36 trial units.A plot of 3 m x 4 m with 25 cm x 25 cm spacing is one unit of the experiment.10 randomly sampled plants in one experimental unit were taken.After 21 days, the seedlings are planted.Fertilization with Ponska NPK 300 kg/ha and Urea 250 kg/ha.Ponska NPK and one-third urea were applied one week after planting, and the remaining 45 days later.An integrated control system is used to control pests and diseases.
The variable observed was based on the Rice Plant Characterization and Evaluation System Guide [13], with the following observation components: 50% flowering age (days), number of panicles per m2/number of productive tillers, plant height (cm), density score, 1000 grain weight, number of filled and unfilled grains per panicle, moisture content (%), and grain yield (kg/ha).
Data analysis was by F test analysis and means were tested for significance followed by the Least Significance Difference (LSD) test.Data processing using the SPSS 17.00 program.

Components of growth
The harvest age is influenced by the flowering age; the sooner the flowering age, the earlier the ripening age [10], which is defined by the issuance of interest in approximately 50% of each experimental plot [6].Table 2's flowering age of 50% suggested that the test line flowers 50% faster than the two comparative varieties.The test lines flowered 79 days from seedling on average.One line, BP12280-3f-7-Kn-2-1*B-Lrg-1-10-13, had a longer age than the Ciherang, whereas the other nine lines had a 50% faster flowering period.
The plant height of the test line was higher than the two comparative varieties, with an average of 124 cm.With a height of 120 cm, the lowest line was BP12206f-8-3-2*B-LR-20-4, and the highest line was BP122, 80-4f-Kn-3-1-1*B-Lrg-1-1-7 with a height of 131 cm.The four lines included in the high rice group were BP12280-4f-Kn-3-1-1*B-Lrg-1-1-7, BP12208f-2-2-3*B-Lrg-2-1-7, and BP12280-4f-Kn-3-3-1*B.Lrg.1-1-4-4.Rice plant height in the generative phase is classified into three groups based on [13] guidelines: short plants with a height of 90 cm, medium plants with a height of 125 cm, and plants with a height of >125 cm.According to the [14], Ciherang grows to a height of 107-115 cm.According to the study's findings, the plant height of the comparative varieties was greater when compared to data on rice plant height from the Balai Besar Padi.This could be due to environmental factors that also influence rice plant growth [6].
The average density score is 4, which is defined as a bit fell (density score: 4) since the wind blows pretty vigorously at the location before harvesting.Many factors, including plant nutrition and resistance of the kinds planted, wind conditions, and the administration of high dosages of N and P fertilizers, affect fall, according to [15], which is characterized by bending and plants falling to the ground [16].

Yield components and yield
Table 3 shows that the average weight of 1000 grains is high, at 27 grams.Generally, the test lines weighed 1000 seeds, which was not significantly different from the comparative variety.8 lines showed 1000 grains weight higher than Ciherang, namely BP12280-3f-7- According to [17], the weight of 1000 grains is categorized into three categories: light (25 g), medium (25-30 g), and heavy (>30 g).The Inpari 7 cultivar weighs 1000 grains more than the Ciherang.According to [18], a high grain yield per unit area is increased by a high weight of 1000 grains of rice grain.

Table 1 .
Comparative Varieties and Resistant Line No. Comparative varieties and resistant line 1

Table 2 .
Test line and comparative varieties average growth components.

Table 3 .
The yield components and average yield components of the test lines and comparative varieties.